Theories on why IMDb message boards were closed (and wiped)

My take:
It was to do with 1) the user feedback films were getting and how they influence the all-important 'first fortnight' of box office, and 2) with the open discussions people were having regarding some of the more 'contentious' subject matter relating to films (e.g., political issues associated with films; actors and their non film-specific related endeavours etc.)

To example a couple of specific, potential scenarios: 
• A big budget film got less than desirable reception from its early screening/s, and feedback filtered down ― through websites like IMDb ― and literally turned people away from paying to see a movie; in turn lowering the revenue relative to projected turnover.  Seeing as the first couple of weekends largely make or break films nowadays, this could have been viewed as far too powerful a tool for consumers to have access to, and therefore targeted for 'termination'.
• Powerful stars with influence bringing their weight to bare: Tom Cruise reads some anti-Scientology related back and forth ― perhaps under a film critical of said scammer cult ― and decides to send in the "squirrel busters" to bust up the IMDb love-in.

Preceding the shut-down on Feb 20, I read many topics and opinions suggesting it was all about moderation / trolls / shills, and that IMDb (with its claimed 250,000,000 regular visitors) could not afford the mods required to keep the place respectable.  To me, this is the story they fed to normies and which only normies lapped up.  Had they left the extant posts intact and archived them, I'd be far more inclined to entertain this argument.  However, since they erased all traces of the discussion that took place at the boards, there's no way their intentions came from a wholly wholesome place.

What's far more likely, in my opinion, is that sponsors, and the like, sent not-to-ambiguous encouragement to websites, like IMDb, to either start implementing Gestapo-like policing of its communal message boards ― particularly for material that was deemed 'inauspicious' for the industry (even if it was edifying for consumers) ― or risk losing $upport.

I'll cite an anecdote of my own to buttress my claim:
Posted a "Hollywood Jews are vindictive" thread a couple of months before the shut-down, in light of Mel Gibson's return to directing (Hacksaw Ridge).  It got a few responses (largely in agreement).  A few weeks later, without as much as a by your leave, all my posts (for ~3.5 years) were purged...!  Around that time, I had not posted many topics ― much less contentious ones ― and had not received any moderations (I knew of) or any warnings (if applicable).  Yet, after I made said post, within a couple of weeks, all my posting history was wiped.

So, I posit that the IMDb discussion boards were closed (and wiped) because TPTB did not like what they read and they felt it potentially affected their money-making and propaganda disseminating ventures.